Hi,

The current behaviour of ssmtp is to leave unchanged the TO: field.
However, many monitoring services (like changetrack) will mail to 'root'
without the @FQDN part. This is allowed and any full featured MTA like
postfix will add this information by default on delivery (though it can
be disabled). For more information look for append_at_myorigin at:
http://www.postfix.org/postconf.5.html#append_at_myorigin

Please make ssmtp add @FQDN to any destination address that doesn't have
and explicit domain set. This should be configurable if you prefer so,
but the default should be ON.
This is a feature request for upstream sstmp, not to be confused with
Debian bug#131940 which requested the opposite action (to remove or
rewrite the @FQDN from destination email addresses).

Thanks